import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        Scanner in = new Scanner(System.in);
        long a=in.nextLong();
        long b=in.nextLong();
        a=(a+b)/2;
        a=a%1000000007;
        long t=in.nextLong();
        System.out.println(pow(a,t));
    }
    public static long pow(long a,long t){
        if(t==0){
            return 1;
        }
        if(t==1){
            return a%1000000007;
        }
        if(t%2==1){
            return (a*(pow(a,t-1)))%1000000007;
        }
        long half = pow(a,t/2)%1000000007;
        return (half*half)%1000000007;
    }
}